Breitenbeek
| Location | between Sankt Andreasberg and Bad Lauterberg in the Harz Mountains in Lower Saxony,  Germany |
|---|---|
| Length | over 6 km |
| Source height | over 620 m |
| Mouth | Sperrlutter 51°39′45″N 10°30′23″E / 51.662444°N 10.506444°E |
| Mouth height | 360 m |
| Descent | ca. 260 m |
| Basin | Sperrlutter → Oder → Rhume → Leine → Aller → Weser |
| Reservoirs passed | Engelsburger Teiche |
The Breitenbeek is a roughly 6.3 km (4 mi) long tributary of the Sperrlutter in the Harz Mountains of central Germany. It rises at over 620 m in the vicinity of the Rehbergklinik in Oderberg. It then flows initially southwards through the Engelsburger Teiche, before it joins the Sperrlutter at 360 m. The Breitenbeek is the largest tributary of the Sperrlutter.